text: from unittest import skipUnless
  
  from django.core.management.color import no_style
  from django.db import connection
  from django.test import TestCase
  
  from .models import Article, IndexTogetherSingleList
  
  
  class CreationIndexesTests(TestCase):
      """
      Test index handling by the to-be-deprecated connection.creation interface.
      """
      def test_index_together(self):
          index_sql = connection.creation.sql_indexes_for_model(Article, no_style())
          self.assertEqual(len(index_sql), 1)
  
      def test_index_together_single_list(self):
          # Test for using index_together with a single list (#22172)
          index_sql = connection.creation.sql_indexes_for_model(IndexTogetherSingleList, no_style())
          self.assertEqual(len(index_sql), 1)
  
      @skipUnless(connection.vendor == 'postgresql',
          "This is a postgresql-specific issue")
      def test_postgresql_text_indexes(self):
          """Test creation of PostgreSQL-specific text indexes (#12234)"""
          from .models import IndexedArticle
          index_sql = connection.creation.sql_indexes_for_model(IndexedArticle, no_style())
          self.assertEqual(len(index_sql), 5)
          self.assertIn('("headline" varchar_pattern_ops)', index_sql[1])
          self.assertIn('("body" text_pattern_ops)', index_sql[3])
          # unique=True and db_index=True should only create the varchar-specific
          # index (#19441).
          self.assertIn('("slug" varchar_pattern_ops)', index_sql[4])
  
      @skipUnless(connection.vendor == 'postgresql',
          "This is a postgresql-specific issue")
      def test_postgresql_virtual_relation_indexes(self):
          """Test indexes are not created for related objects"""
          index_sql = connection.creation.sql_indexes_for_model(Article, no_style())
          self.assertEqual(len(index_sql), 1)
  
  
  class SchemaIndexesTests(TestCase):
      """
      Test index handling by the db.backends.schema infrastructure.
      """
      def test_index_together(self):
          editor = connection.schema_editor()
          index_sql = editor._model_indexes_sql(Article)
          self.assertEqual(len(index_sql), 1)
          # Ensure the index name is properly quoted
          self.assertIn(
              connection.ops.quote_name(
                  editor._create_index_name(Article, ['headline', 'pub_date'], suffix='_idx')
              ),
              index_sql[0]
          )
  
      def test_index_together_single_list(self):
          # Test for using index_together with a single list (#22172)
          index_sql = connection.schema_editor()._model_indexes_sql(IndexTogetherSingleList)
          self.assertEqual(len(index_sql), 1)
  
      @skipUnless(connection.vendor == 'postgresql',
          "This is a postgresql-specific issue")
      def test_postgresql_text_indexes(self):
          """Test creation of PostgreSQL-specific text indexes (#12234)"""
          from .models import IndexedArticle
          index_sql = connection.schema_editor()._model_indexes_sql(IndexedArticle)
          self.assertEqual(len(index_sql), 5)
          self.assertIn('("headline" varchar_pattern_ops)', index_sql[2])
          self.assertIn('("body" text_pattern_ops)', index_sql[3])
          # unique=True and db_index=True should only create the varchar-specific
          # index (#19441).
          self.assertIn('("slug" varchar_pattern_ops)', index_sql[4])
  
      @skipUnless(connection.vendor == 'postgresql',
          "This is a postgresql-specific issue")
      def test_postgresql_virtual_relation_indexes(self):
          """Test indexes are not created for related objects"""
          index_sql = connection.schema_editor()._model_indexes_sql(Article)
          self.assertEqual(len(index_sql), 1)
  